Heart wall tension reduction apparatus and method

ABSTRACT

An apparatus for treatment of a failing heart by reducing the wall tension therein. In one embodiment, the apparatus includes a tension member for drawing at least two walls of a heart chamber toward each other. Methods for placing the apparatus on the heart are also provided.

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application is a continuation-in-part of U.S. applicationSer. No. 08/778,277, filed Jan. 2, 1997, entitled “HEART WALL TENSIONREDUCTION APPARATUS”.

FIELD OF THE INVENTION

[0002] The present invention pertains to the field of apparatus fortreatment of a failing heart. In particular, the apparatus of thepresent invention is directed toward reducing the wall stress in thefailing heart.

BACKGROUND OF THE INVENTION

[0003] The syndrome of heart failure is a common course for theprogression of many forms of heart disease. Heart failure may beconsidered to be the condition in which an abnormality of cardiacfunction is responsible for the inability of the heart to pump blood ata race commensurate with the requirements of the metabolizing tissues,or can do so only at an abnormally elevated filling pressure. There aremany specific disease processes that can lead to heart failure with aresulting difference in pathophysiology of the failing heart, such asthe dilatation of the left ventricular chamber. Etiologies that can leadto this form of failure include idiopathic cardiomyopathy, viralcardiomyopathy, and ischemic cardiomyopathy.

[0004] The process of ventricular dilatation is generally the result ofchronic volume overload or specific damage to the myocardium. In anormal heart that is exposed to long term increased cardiac outputrequirements, for example, that of an athlete, there is an adaptiveprocess of slight ventricular dilation and muscle myocyte hypertrophy.In this way, the heart fully compensates for the increased cardiacoutput requirements. With damage to the myocardium or chronic volumeoverload, however, there are increased requirements put on thecontracting myocardium to such a level that this compensated state isnever achieved and the heart continues to dilate.

[0005] The basic problem with a large dilated left ventricle is thatthere is a significant increase in wall tension and/or stress bothduring diastolic filling and during systolic contraction. In a normalheart, the adaptation of muscle hypertrophy (thickening) and ventriculardilatation maintain a fairly constant wall tension for systoliccontraction. However, in a failing heart, the ongoing dilatation isgreater than the hypertrophy and the result is a rising wall tensionrequirement for systolic contraction. This is felt to be an ongoinginsult to the muscle myocyte resulting in further muscle damage. Theincrease in wall stress is also true for diastolic filling.Additionally, because of the lack of cardiac output, there is generallya rise in ventricular filling pressure from several physiologicmechanisms. Moreover, in diastole there is both a diameter increase anda pressure increase over normal, both contributing to higher wall stresslevels. The increase in diastolic wall stress is felt to be the primarycontributor to ongoing dilatation of the chamber.

[0006] Prior art treatments for heart failure fall into three generallycategories. The first being pharmacological, for example, diuretics. Thesecond being assist systems, for example, pumps. Finally, surgicaltreatments have been experimented with, which are described in moredetail below.

[0007] With respect to pharmacological treatments, diuretics have beenused to reduce the workload of the heart by reducing blood volume andpreload. Clinically preload is defined in several ways including leftventricular end diastolic pressure (LVEDP), or left ventricular enddiastolic volume (LVEDV). Physiologically, the preferred definition isthe length of stretch of the sarcomere at end diastole. Diuretics reduceextra cellular fluid which builds in congestive heart failure patientsincreasing preload conditions. Nitrates, arteriolar vasodilators,angiotensin converting enzyme inhibitors have been used to treat heartfailure through the reduction of cardiac workload through the reductionof afterload. Afterload may be defined as the tension or stress requiredin the wall of the ventricle during ejection. Inotropes like digoxin arecardiac glycosides and function to increase cardiac output by increasingthe force and speed of cardiac muscle contraction. These drug therapiesoffer some beneficial effects but do not stop the progression of thedisease.

[0008] Assist devices include mechanical pumps and electricalstimulators. Mechanical pumps reduce the load on the heart by performingall or part of the pumping function normally done by the heart.Currently, mechanical pumps are used to sustain the patient while adonor heart for transplantation becomes available for the patient.Electrical stimulation such as bi-ventricular pacing have beeninvestigated for the treatment of patients with dilated cardiomyopathy.

[0009] There are at least three surgical procedures for treatment ofheart failure: 1) heart transplant; 2) dynamic cardiomyoplasty; and 3)the Batista partial left ventriculectomy. Heart transplantation hasserious limitations including restricted availability of organs andadverse effects of immunosuppressive therapies required following hearttransplantation. Cardiomyoplasty includes wrapping the heart withskeletal muscle and electrically stimulating the muscle to contractsynchronously with the heart in order to help the pumping function ofthe heart. The Batista partial left ventriculectomy includes surgicallyremodeling the left ventricle by removing a segment of he muscular wall.This procedure reduces the diameter of the dilated heart, which in turnreduces the loading of the heart. However, this extremely invasiveprocedure reduces muscle mass of the heart.

SUMMARY OF THE INVENTION

[0010] The present invention pertains to a non-pharmacological, passiveapparatus and method for the treatment of a failing heart. The device isconfigured to reduce the tension in the heart wall. It is believed toreverse, stop or slow the disease process of a failing heart as itreduces the energy consumption of the failing heart, decreasesisovolumetric contraction, increases sarcomere shortening duringcontraction and increases isotonic shortening which in turn increasesstroke volume. The device reduces wall tension during diastole andsystole.

[0011] In one embodiment, the apparatus includes a tension member fordrawing at least two walls of the heart chamber toward each other toreduce the radius or area of the heart chamber in at least one crosssectional plane. The tension member has anchoring members disposed atopposite ends engagement with the heart or chamber wall.

[0012] In another embodiment, the apparatus includes a compressionmember for drawing at least two walls of a heart chamber toward eachother. In one embodiment, the compression member includes a balloon. Inanother embodiment of the apparatus, a frame is provided for supportingthe compression member.

[0013] Yet another embodiment of the invention includes a clamp havingtwo ends biased toward one another for drawing at least two walls of aheart chamber toward each other. The clamp includes at least two endshaving atraumatic anchoring member disposed thereon for engagement withthe heart or chamber wall.

[0014] In yet another embodiment, a heart wall tension reductionapparatus is provided which includes a first tension member having twooppositely disposed ends and first and second elongate anchor members. Asecond tension member can be provided. One of the elongate anchors maybe substituted for by two smaller anchors.

[0015] In an alternate embodiment of the heart wall tension reductionapparatus, an elongate compression member can be provided. First andsecond elongate lever members preferably extend from opposite ends ofthe compression member. A tension member extends between the first andsecond lever members.

[0016] The compression member of the above embodiment can be disposedexterior to, or internally of the heart. The tension member extendsthrough the chamber or chambers to bias the lever members toward theheart.

[0017] In yet another embodiment of a heart wall tension reductionapparatus in accordance with the present invention, a rigid elongateframe member is provided. The frame member can extend through one ormore chambers of the heart. One or more cantilever members can bedisposed at opposite ends of the frame member. Each cantilever memberincludes at least one atraumatic cad disposed thereon. The atraumaticpads disposed at opposite ends of the frame member can be biased towardeach other to compress the heart chamber.

[0018] One method of placing a heart wall tension apparatus or splint ona human hearts includes the step of extending a hollow needle through atleast one chamber of the heart such that each end of the needle isexternal to the chamber. A flexible leader is connected to a first endof a tension member. A second end of the tension member is connected toan atraumatic pad. The leader is advanced through the needle from oneend of he needle to the other. The leader is further advanced until thesecond end of the tension member is proximate the heart and the firstend of the tension member is external to the heart. A second atraumaticpad is connected to the first end of the tension member such that thefirst and second atraumatic pads engage the heart.

[0019] An alternate method of placing the heart wall tension reductionapparatus on the heart includes the step of extending a guide memberthrough at least one chamber of the heart such that each end of theguide member is external to the chamber. A tension member for use inthis method has at least one lumen extending through at least a portionof the member. The guide member is placed in the lumen. The tensionmember is advanced over the guide member such that a first end of thetension member is disposed to one side of and external to the heart anda second end of the tension member is disposed to an opposite side ofand external to the heart. A first atraumatic pad is connected to oneend of the tension member and a second atraumatic pad is connected tothe opposite end of the tension member.

[0020] Yet another method of placing a heart wall tension apparatus on aheart includes the step of extending a needle having a flexible tensionmember releasably connected thereto through at least one chamber of theheart such that opposite ends of the tension member are external to thechamber and exposed on opposite sides of the chamber. The needle isremoved from the tension member. Then first and second atraumatic padsare connected to the tension member at opposite ends of the tensionmember.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021]FIG. 1 is a transverse cross-section of the left and rightventricles of a human heart showing the placement of a splint inaccordance with the present invention;

[0022]FIG. 2 is a transverse cross-section of the left and rightventricles of a human heart showing the placement of a balloon device inaccordance with the present invention;

[0023]FIG. 3 is a transverse cross-section of the left and rightventricles of a human heart showing the placement of an externalcompression frame structure in accordance with the present invention;

[0024]FIG. 4 is a transverse cross-section of the left and rightventricles of a human heart showing a clamp in accordance with thepresent invention;

[0025]FIG. 5 is a transverse cross-section of the left and rightventricles of a human heart showing a three tension member version ofthe splint of FIG. 1;

[0026]FIG. 6 is a transverse cross-section of the left and rightventricles of a human heart showing a four tension member version of thesplint shown in FIG. 1;

[0027]FIG. 7 is a vertical cross-sectional view of the left ventricle ofa human heart showing an alternate version of the splint in accordancewith the present invention;

[0028]FIG. 8 is an end of the splint shown in FIG. 7;

[0029]FIG. 9 is a vertical cross-sectional view of a chamber of a humanheart showing another alternative embodiment of the splint in accordancewith the present invention;

[0030]FIG. 10 is a vertical cross-section of a chamber of a human heartshowing another alternative configuration splints in accordance with thepresent invention;

[0031]FIG. 11 is a vertical cross-sectional view of a chamber of a humanheart showing another embodiment of a splint in accordance with thepresent invention;

[0032]FIG. 12 is a vertical cross-sectional view of a chamber of a humanheart showing another embodiment of the splint in accordance with thepresent invention;

[0033]FIG. 13 is a vertical cross-sectional view of a chamber of a humanheart showing a compression member version of the splint in accordancewith the present invention;

[0034]FIG. 14 is a vertical cross-sectional view of a chamber of a humanheart showing another version of the splint shown in FIG. 13;

[0035]FIG. 15 is a vertical cross-sectional view of a chamber of a humanheart showing a frame member version of the splint in accordance withthe present invention;

[0036]FIG. 16 is an end view of the splint of FIG. 15;

[0037]FIG. 17 is a vertical cross-section of the left ventricle andatrium, the left ventricle having scar tissue;

[0038]FIG. 18 is a vertical cross-section of the heart of FIG. 7 showingthe splint of FIG. 1 drawing the scar tissue toward the opposite wall ofthe left ventricle;

[0039]FIG. 19 is a vertical cross-section of the left ventricle andatrium of a human heart showing a version of the splint of FIG. 1 havingan elongate anchor bar;

[0040]FIG. 20 is a side view of an undeployed hinged anchor member;

[0041]FIG. 21 is a side view of a deployed hinged anchor member of FIG.10;

[0042]FIG. 22 is a cross-sectional view of an captured ball anchormember;

[0043]FIG. 23 is a perspective view of a cross bar anchor member;

[0044]FIG. 24 is a vertical cross-sectional view of a chamber of a humanheart showing a needle used for placement of splint in accordance withthe present invention;

[0045]FIG. 25 is a view of the heart and needle of FIG. 24 showing atension member being placed in the heart;

[0046]FIG. 26 is a view of the heart shown in FIG. 24 wherein oppositelydisposed anchor pads are being joined by a tension member;

[0047]FIG. 27 is a view of the heart of FIG. 24, wherein two oppositelydisposed anchor pads have been joined by two tension members;

[0048]FIG. 29 is a view of a tension member having a lumen extendingtherethrough;

[0049]FIG. 29 is a view of a tension member having lumens extendingtherethrough;

[0050]FIG. 30 is a vertical cross-sectional view of a chamber of theheart and two pads, and a needle extending therethrough;

[0051]FIG. 31 is a vertical cross-sectional view of a chamber of theheart showing a guidewire extending therethrough;

[0052]FIG. 32 is a view of the heart of FIG. 31, and two pads, and aguidewire extending therethrough;

[0053]FIG. 33 is a vertical cross-sectional view of a chamber of theheart showing a needle connected to a tension member being inserted intothe chamber;

[0054]FIG. 34 is a vertical cross-sectional view of a chamber of a heartshowing two anchors connected by a tension member;

[0055]FIG. 35 is a vertical cross-sectional view of a chamber of theheart, showing a band surrounding the heart;

[0056]FIG. 36 is a idealized cylindrical model of a left ventricle of ahuman heart;

[0057]FIG. 37 is a splinted model of the left ventricle of FIG. 14;

[0058]FIG. 38 is a transverse cross-sectional view of FIG. 15 showingvarious modeling parameters;

[0059]FIG. 39 is a transverse cross-section of the splinted leftventricle of FIG. 15 showing a hypothetical force distribution; and

[0060]FIG. 40 is a second transverse cross-sectional view of the modelleft ventricle of FIG. 15 showing a hypothetical force distribution.

DETAILED DESCRIPTION OF THE INVENTION

[0061] Referring now to the drawings wherein like reference numeralsrefer to like elements throughout the several views, FIG. 1 shows atransverse cross-section of a left ventricle 10 and a right ventricle 12of a human heart 14. Extending through the left ventricle is a splint 16including a tension member 18 and oppositely disposed anchors 20. Splint16 as shown in FIG. 1 has been positioned to draw opposite walls of leftventricle 10 toward each other to reduce the “radius” of the leftventricular cross-section or the cross-sectional area thereof to reduceleft ventricular wall stresses. It should be understood that althoughthe splint 16 and the alternative devices disclosed herein are describedin relation to the left ventricle of a human heart, these devices couldalso be used to reduce the radius or cross-sectional area of the otherchambers of a human heart in transverse or vertical directions, or at anangle between the transverse and vertical.

[0062]FIG. 2 discloses an alternate embodiment of the present invention,wherein a balloon 200 is deployed adjacent the left ventricle. The sizeand degree of inflation of the balloon can be varied to reduce theradius or cross-sectional area of left ventricle 10 of heart 14.

[0063]FIG. 3 shows yet another alternative embodiment of the presentinvention deployed with respect to left ventricle 10 of human heart 14.Here a compression frame structure 300 is engaged with heart 14 atatraumatic anchor pads 310. A compression member 312 having anatraumatic surface 314 presses against a wall of left ventricle 10 toreduce the radius or cross-sectional area thereof.

[0064]FIG. 4 is a transverse cross-sectional view of human heart 14showing yet another embodiment of the present invention. In this case aclamp 400 having atraumatic anchor pads 410 biased toward each other isshown disposed on a wall of left ventricle 10. Here the radius orcross-sectional area of left ventricle 10 is reduced by clamping off theportion of the wall between pads 410. Pads 410 can be biased toward eachother and/or can be held together by a locking device.

[0065] Each of the various embodiments of the present inventiondisclosed in FIGS. 1-4 can be made from materials which can remainimplanted in the human body indefinitely. Such biocompatible materialsare well-known to those skilled in the art of clinical medical devices.

[0066]FIG. 5 shows an alternate embodiment of the splint of FIG. 1referred to in FIG. 5 by the numeral 116. The embodiment 116 shown inFIG. 5 includes three tension members 118 as opposed to a single tensionmember 18 as shown in FIG. 1. FIG. 6 shows yet another embodiment of thesplint 216 having four tension members 218. It is anticipated that insome patients, the disease process of the failing heart may be soadvanced that three, four or more tension members may be desirable toreduce the heart wall stresses more substantially than possible with asingle tension member as shown in FIG. 1.

[0067]FIG. 7 is a partial vertical cross-section of human heart 14showing left ventricle 10. In FIG. 7, another splint embodiment 316 isshown having a tension member 318 extending through left ventricle 10.On opposite ends of tension member 318 are disposed elongate anchors orpads 320. FIG. 8 is an end view of tension member 318 showing elongateanchor 320.

[0068]FIG. 9 shows another embodiment of a splint 416 disposed in apartial vertical cross-section of human heart 14. Splint 416 includestwo elongate anchors or pads 420 similar to those shown in FIGS. 7 and8. In FIG. 9, however, two tension members 418 extend through leftventricle 10 to interconnect anchors 420 on opposite sides of heart.

[0069]FIG. 10 is a vertical cross section of heart 14 showing leftventricle 10. In this case, two splints 16 are disposed through leftventricle 10 and vertically spaced from each other to resemble theconfiguration of FIG. 9.

[0070]FIG. 11 is a vertical cross sectional view of the left ventricleof heart 14. Two alternate embodiment splints 516 are shown extendingthrough left ventricle 10. Each splint 516 includes two tension members518 interconnecting two anchors or pads 520.

[0071]FIG. 12 is yet another vertical cross sectional view of leftventricle 10 of heart 14. An alternate embodiment 616 of the splint isshown extending through left ventricle 10. Splint 616 includes anelongate anchor pad 620 and two shorter anchors or pads 621. Splint 616includes two tension members 618. Each tension member 618 extendsbetween anchors 620 and respective anchors 621.

[0072]FIG. 13 is a vertical cross sectional view of left ventricle 10 ofheart 14. A splint 50 is shown disposed on heart 14. Splint 50 includesa compression member 52 shown extending through left ventricle 10.Opposite ends of compression member 52 are disposed exterior to leftventricle 10. Lever members 54 extend from each end of compressionmember 52 upwardly along the exterior surface of ventricle 10. A tensionmember 56 extends between lever members 54 to bias lever members 54toward heart 14 to compress chamber 10.

[0073] Compression member 52 should be substantially rigid, but levermembers 54 and to some degree compression member 52 should be flexibleenough to allow tension member 56 to bias lever members 54 toward heart14. Alternately, lever members 54 could be hinged to compression member52 such that lever members 54 could pivot about the hinge when biasedtoward heart 14 by tension member 56.

[0074]FIG. 14 shows an alternate embodiment 156 of the splint shown inFIG. 13. In this case lever members 154 are longer than members 54 ascompression member 152 of splint 150 has been disposed to the exteriorof left ventricle 10.

[0075]FIG. 15 is a vertical cross sectional view of left ventricle 10 ofheart 14. An alternate embodiment 250 of the splint is shown on heart14. A preferably relatively rigid frame member 256 extends throughventricle 10. Disposed on opposite ends of frame 250 are cantilevermember 254. Disposed on cantilever members 254 are atraumatic pads 258.Cantilever members 254 can be positioned along frame member 256 suchthat atraumatic pads 258 press against heart 14 to compress chamber 10.FIG. 16 is an end view of frame member 256 showing cantilever members254 and pads 258.

[0076] It should be understood that each of the embodiments describedabove should be formed from suitable biocompatible materials known tothose skilled in the art. The tension members can be formed fromflexible or relatively more rigid material. The compression members andframe member should be formed from generally rigid material which mayflex under load, but generally hold its shape.

[0077]FIG. 17 is a partial vertical cross-section of human heart 14showing left ventricle 10 and left atrium 22. As shown in FIG. 7, heart14 includes a region of scar tissue 24 associated with an aneurysm orischemia. As shown in FIG. 7, the scar tissue 24 increases the radius orcross-sectional area of left ventricle 10 in the region affected by thescar tissue. Such an increase in the radius or cross-sectional area ofthe left ventricle will result in greater wall stresses on the walls ofthe left ventricle.

[0078]FIG. 18 is a vertical cross-sectional view of the heart 14 asshown in FIG. 7, wherein a splint 16 has been placed to draw the scartissue 24 toward an opposite wall of left ventricle 10. As a consequenceof placing splint 16, the radius or cross-sectional area of the leftventricle affected by the scar tissue 24 is reduced. The reduction ofthis radius or cross-sectional area results in reduction in the wallstress in the left ventricular wall and thus improves heart-pumpingefficiency.

[0079]FIG. 19 is a vertical cross-sectional view of left ventricle 10and left atrium 22 of heart 14 in which a splint 16 has been placed. Asshown in FIG. 9, splint 15 includes an alternative anchor 26. The anchor26 is preferably an elongate member having a length as shown in FIG. 9substantially greater than its width (not shown). Anchor bar 26 might beused to reduce the radius or cross-sectional area of the left ventriclein an instance where there is generalized enlargement of left ventricle10 such as in idiopathic dilated cardiomyopathy. In such an instance,bar anchor 26 can distribute forces more widely than anchor 20.

[0080]FIGS. 20 and 21 are side views of a hinged anchor 28 which couldbe substituted for anchors 20 in undeployed and deployed positionsrespectively. Anchor 28 as shown in FIG. 20 includes two legs similar tobar anchor 26. Hinged anchor 28 could include additional legs and thelength of those legs could be varied to distribute the force over thesurface of the heart wall. In addition there could be webbing betweeneach of the legs to give anchor 28 an umbrella-like appearance.Preferably the webbing would be disposed on the surface of the legswhich would be in contact with the heart wall.

[0081]FIG. 22 is a cross-sectional view of a capture ball anchor 30.Capture ball anchor 30 can be used in place of anchor 20. Capture ballanchor 30 includes a disk portion 32 to distribute the force of theanchor on the heart wall, and a recess 34 for receiving a ball 36affixed to an end of tension member 18. Disk 32 and recess 34 include aside groove which allows tension member 38 to be passed from an outsideedge of disk 32 into recess 34. Ball 36 can then be advanced into recess34 by drawing tension member 18 through an opening 38 in recess 34opposite disk 32.

[0082]FIG. 23 is a perspective view of a cross bar anchor 40. The crossbar anchor 40 can be used in place of anchors 20. The anchor 40preferably includes a disk or pad portion 42 having a cross bar 44extending over an opening 46 in pad 42. Tension member 18 can beextended through opening 46 and tied to cross bar 42 as shown.

[0083] In use, the various embodiments of the present invention areplaced in or adjacent the human heart to reduce the radius orcross-section area of at least one chamber of the heart. This is done toreduce wall stress or tension in the heart or chamber wall to slow, stopor reverse failure of the heart. In the case of the splint 16 shown inFIG. 1, a canula can be used to pierce both walls of the heart and oneend of the splint can be advanced through the canula from one side ofthe heart to the opposite side where an anchor can be affixed ordeployed. Likewise, an anchor is affixed or deployed at the opposite endof splint 16.

[0084]FIG. 24 is a vertical cross-sectional view of a chamber of a heart14. A needle 60 having a stylet inserted therethrough is insertedthrough chamber 10. FIG. 25 shows needle 60 disposed in heart 40 asshown in FIG. 24. In FIG. 25, stylet 6 has been removed. A tensionmember 64 having a flexible leader 66 attached to one end of tensionmember 64, is threaded through needle 60 and an anchor 68.

[0085] As shown in FIG. 25, tension member 64 includes a generallyelongate cylindrical shaft 70 having two generally cylindrical ends 72.Ends 72 preferably have a greater diameter than shaft 70. Also shown inFIG. 25 is a perspective view of anchor 68 showing an opening 73extending through anchor 68. Opening 73 includes a first cylindricallyshaped opening 74 extending entirely through anchor 68. The diameter ofopening 74 is preferably slightly greater than the diameter of end 72 oftension member 64. A groove 76 having a width preferably slightlygreater than that of shaft 70 of tension member 64 extends from opening74 to a generally cylindrical opening 78. Generally cylindrical opening78 has a diameter approximately equal to end 72. Unlike opening 74,however, opening 78 includes a reduced base opening 80 which has a widthapproximately equal to that of groove 76. The width of the opening 80 isalso less than the diameter of end 72 of tension member 64.

[0086] It can be appreciated that tension member 64 can be advancedthrough opening 74 until shaft 70 is disposed therein. Shaft 70 can bethen slid transversely through groove 76. Tension member 64 can then beadvanced further through opening 73 until end portion 72 enters opening78 and seats against base 80.

[0087]FIG. 26 shows the view of heart 14 shown in FIG. 25. Needle 60 hasbeen removed from heart 14. Tension member 64 has been advanced intochamber 10 and anchor 68 connected thereto is engaging the heart wall.Leader 66 has been advanced through yet another anchor 68 disposed onthe opposite side of heart 14.

[0088]FIG. 27 is a view of heart 14 of FIG. 26. Two tension member 64have been advanced through chamber 10. Each tension member has beenseated in respective opening 78 against respective bases 80 to form asplint in a configuration such as that shown in FIG. 9.

[0089] It can be appreciated that each of the other tension membersplints configurations can be placed on the heart in a similar manner.It can also be appreciated that anchors 68 could initially be heldagainst the heart and needle 60 advanced through anchors 68 and chamber10 prior to extending leader 66 through the needle.

[0090]FIG. 28 is a perspective view of a tension member 164 inaccordance with the present invention. Tension member 164 is similar totension member 64 described above in that it has an elongate, generallycylindrical shaft 170 and generally cylindrical ends 172. A lumen,however, extends longitudinally through tension member 164 along axis A.

[0091]FIG. 29 is a perspective view of yet another embodiment of thetension member 264. Tension member 264, is similar to tension member164, and includes an elongate cylindrical shaft 270 and cylindrical ends272. Lumens 282, however, extend through ends 272 aligned along axis P.

[0092]FIG. 30 is a vertical, cross-sectional view of left ventricle 10of heart 14. Anchors 68 have been placed on opposite sides of heart 14.A needle 160 extends through the lumen of tension member 164, leftventricle 10 and openings 73 in anchors 68. It can be appreciated thattension member 64 can be advanced through anchors 68 and left ventricle10 and be seated within openings 78 as described above with respect totension member 64.

[0093]FIG. 31 is a vertical, cross-sectional view of left ventricle 10of heart 14. A needle 60 has been advanced through the wall of leftventricle 10 and a guidewire 162 has been advanced through needle 60.

[0094]FIG. 32 is the same view of heart 14 as shown in FIG. 32. Needle60, however, has been removed from heart 14 while guidewire 162 remainsin position. Anchors 68 have been placed on guidewire 162, on oppositesides of left ventricle 10. Tension member 264 has been threaded ontoguidewire 162 through lumens 282. It can be appreciated that asdiscussed above with respect to tension member 164 above, tension member264 can be advanced through left ventricle 10 such that ends 272 oftension member 264 seat in respective openings 78 against base 80.

[0095]FIG. 33 is a vertical, cross-sectional view of left ventricle 10of heart 14. In FIG. 34, flexible tension member 364 has been connectedto a needle 360. Needle 360 is shown being advanced into left ventricle10 through a ventricle wall.

[0096]FIG. 34 is the same view of heart 14 as shown in FIG. 33 exceptthat tension member 364 has been advanced entirely through leftventricle 10 and anchors 68. Knots 384 have been tied at the ends oftension member 364 to prevent the ends of tension member 364 frompassing through opening 73 of anchors 68.

[0097] It can be appreciated that the methods described above to advancethe tension members through the ventricles can be repeated to advancethe desired number of tension members through the ventricle for aparticular configuration. The length of the tension members can bedetermined based upon the size and condition of the patient's heart. Itshould also be noted that although the left ventricle has been referredto here for illustrative purposes, that the apparatus and methods ofthis invention can also be used to splint multiple chambers of apatient's heart as well as the right ventricle or either atrium.

[0098]FIG. 35 is a vertical cross-section of left ventricle 10 of heart14. Disposed about heart 14 is a band 716. Band 716 is shown as beingsized relative to the heart such that the heart's radius orcross-sectional area in a plane parallel to the length of the band isreduced relative to the radius at that location prior to placement ofthe band on the heart. The length of the heart perpendicular to the bandis also increased. The band may be formed from a continuous ribbon ofelastomeric material or from other biocompatible materials which aresufficiently strong to provide the desired effect of heart radiusreduction and lengthening.

[0099]FIG. 36 is a view of a cylinder or idealized heart chamber 48which is used to illustrate the reduction of wall stress in a heartchamber as a result of deployment of the splint in accordance with thepresent invention. The model used herein and the calculations related tothis model are intended merely to illustrate the mechanism by which wallstress is reduced in the heart chamber. No effort is made herein toquantify the actual reduction which would be realized in any particularin vivo application.

[0100]FIG. 37 is a view of the idealized heart chamber 48 of FIG. 36wherein the chamber has been splinted along its length L such that a“figure eight” cross-section has been formed along the length thereof.It should be noted that the perimeter of the circular transversecross-section of the chamber in FIG. 36 is equal to the perimeter of thefigure eight transverse cross-section of FIG. 37. For purposes of t ismodel, opposite lobes of the figure in cross-section are assumed to bemirror images.

[0101]FIG. 38 shows various parameters of the FIG. 1 cross-section ofthe splinted idealized heart chamber of FIG. 37. Where l is the lengthof the splint between opposite walls of the chamber, R₂ is the radius ofeach lobe, θ is the angle between the two radii of one lobe whichextends to opposite ends of the portion of the splint within chamber 48and h is the height of the triangle formed by the two radii and theportion of the splint within the chamber 48 (R₁ is the radius of thecylinder of FIG. 36). These various parameters are related as follows:

[0102] h=R₂ COS (θ/2)

[0103] l=2 R₂ SIN (θ/2)

[0104] R₂=R₁π/2π−θ)

[0105] From these relationships, the area of the figure eightcross-section can be calculated by:

A₂=2π(R₂)² (1−θ/2π)+hl

[0106] Where chamber 48 is unsplinted as shown in FIG. 35 A₁, theoriginal cross-sectional area of the cylinder is equal to A₂ whereθ=180°, h=0 and l=2R₂. Volume equals A₂ times length L andcircumferential wall tension equals pressure within the chamber times R₂times the length L of the chamber.

[0107] Thus, for example, with an original cylindrical radius of fourcentimeters and a pressure within the chamber of 140 mm of mercury, thewall tension T in the walls of the cylinder is 104.4 newtons. When a3.84 cm splint is placed as shown in FIGS. 37 and 38 such that l=3.84cm, the wall tension T is 77.33 newtons.

[0108]FIGS. 39 and 40 show a hypothetical distribution of wall tension Tand pressure F for the figure eight cross-section. As θ goes from 180°to 0°, tension T₂ in the splint goes from 0 to a 2T load where thechamber walls carry a T load.

[0109] In yet another example, assuming that the chamber length L is aconstant 10 cm, the original radius R₁ is 4 cm, at a 140 mmHg thetension in the walls is 74.7 N. If a 4.5 cm splint is placed such thatl=4.5 cm, the wall tension will then be 52.8 N.

[0110] It will be understood that this disclosure is in many isrespects, is only illustrative. Changes may be made in details,particularly in matters of shape, size, material, and arrangement ofparts without exceeding the scope of the invention. Accordingly, thescope of the invention is as defined in the language of the appendedclaims.

What is claimed is:
 1. A heart wall tension reduction apparatus, comprising: a first tension member having two oppositely disposed ends; and first and second anchor members, the first anchor member being disposed proximate one end of the tension member and second anchor member being disposed proximate the opposite end of the tension member.
 2. The heart wall tension reduction apparatus in accordance with claim 1, wherein the first anchor member comprises a first pad having a length and a width, and the second anchor member comprises a second pad having a length and a width, and the first and second pad each have two lengthwise ends.
 3. The heart wall tension reduction apparatus in accordance with claim 2, wherein the length of the pads is greater than the width of the respective pad.
 4. A heart wall tension reduction apparatus in accordance with claim 2, further comprising a second tension member having two oppositely disposed ends; and one lengthwise end of the first pad is disposed proximate one end of the first tension member, and the opposite lengthwise end of the first pad is disposed proximate one end of the second tension member, and one lengthwise end of the second pad is disposed proximate the end of the first tension member opposite the first pad, and the opposite lengthwise of the second pad is disposed proximate the end of the second tension member opposite the first pad.
 5. The heart wall tension reduction apparatus in accordance with claim 4, wherein the length of the first pad is greater than the width of the respective pads.
 6. The heart wall tension reduction apparatus in accordance with claim 1, further comprising a third anchor member, and a second tension member having two oppositely disposed ends; wherein the third anchor member is disposed proximate one end of the second tension member and the first anchor member is disposed proximate the opposite end of the second tension member.
 7. The heart wall tension reduction apparatus in accordance with claim 6, wherein the first anchor member comprises a first pad having a length and width, and the second anchor member comprises a second pad having a length and a width, and the first and second pads each have two lengthwise ends.
 8. The heart wall tension reduction apparatus in accordance with claim 7, wherein the length of the pads is greater than the width of the respective pad.
 9. The heart wall tension reduction apparatus, comprising: an elongate compression member having first and second ends; first and second elongate lever members, the first lever member extending from the first end of the compression member, and the second lever member extending from the second end of the compression member; and a tension member extending between the first and second lever members.
 10. A heart wall tension reduction apparatus in accordance with claim 9, wherein each of the two lever members have two ends, one end of each of the two lever members is disposed proximate the compression member, the other end each of the two lever members is disposed remotely from he compression member, and the tension member is disposed closer to the ends of the two lever members disposed proximate the compression member than the ends disposed remotely therefrom.
 11. A method of disposing a heart wall tension reduction apparatus on a human heart having a plurality of chambers, comprising the steps of: providing a heart wall tension reduction apparatus including an elongate compression member having first and second ends; first and second elongate lever members, the first lever member extending from the first end of the compression member, and the second lever member extending from the second end of the compression member; a tension member extending between the first and second lever members; and extending the tension member through at least one chamber of the human heart.
 12. A method in accordance with claim 11, further comprising the step of disposing the compression member external to the heart.
 13. The method in accordance with claim 11, further comprising the step of disposing at least a portion of the compression member within the heart.
 14. A heart wall tension reduction apparatus, comprising: a rigid elongate frame member having a first end and a second end; a first cantilever member disposed at the first end of the frame member; and a second cantilever member disposed at the second end of the frame member.
 15. A heart wall tension reduction apparatus in accordance with claim 14, wherein each cantilever member includes at least one atraumatic pad disposed thereon.
 16. A heart wall tension reduction apparatus in accordance with claim 14, further comprising a plurality of cantilever members disposed at the first and second ends of the frame member.
 17. The method of placing a heart wall tension reduction apparatus on a human heart having a plurality of chambers, comprising the steps of: extending a hollow needle through at least one chamber the heart such that each end of the needle is external to the chamber; providing a tension member having first and second ends, and a flexible leader connected to the first end of the tension member; connecting the second end of the tension member to a first atraumatic pad; advancing the leader through the needle from one end of the needle to the other; further advancing the leader until the first atraumatric pad engages the heart and the first end of the tension member is external to the at least one chamber; and connecting the first end of the tension member to a second atraumatic pad such that the second atraumatic pad engages the heart.
 18. The method in accordance with claim 17, wherein the length of the tension member is such that the at least one chamber of the heart is compressed between the first and second atraumatic pads.
 19. The method of placing a heart wall tension reduction apparatus on a heart having a plurality of chambers, comprising the steps of: extending a guide member through at least one chamber of the heart such that each end of the guide member is external to the chamber; providing a tension member having at least one lumen extending therethrough; extending a portion of the guide member through the lumen; advancing the tension member on the guide member such that a first end of the tension member is disposed to one side of and external to the at least one chamber, and a second end of the tension member is disposed to an opposite side of and external to the at least one chamber; and connecting a first atraumatic pad to the first end and a second atraumatic pad to the second end of the tension member.
 20. The method in accordance with claim 19, wherein the length of the tension member is such that the at least one chamber of the heart is compressed between the first and second atraumatic pads.
 21. A method in accordance with claim 19, wherein the guide member includes a needle.
 22. The method in accordance with claim 19, wherein the guide member includes a guidewire.
 23. The method of placing a heart wall tension reduction apparatus on a heart having a plurality of chamber comprising the steps of: extending a needle having a flexible tension member releasably connected thereto through at least one chamber of the heart such that opposite ends of the tension member are external to the chamber and exposed on opposite sides thereof; removing the needle from the tension member; and connecting a first atraumatic pad to one end of the tension member and a second atraumatic pad to the opposite end of the tension member.
 24. A method in accordance with claim 23, wherein the length of the tension member is such that the at least one chamber of the heart is compressed between the first and second atraumatic pads. 